It was just a wee bit too cold for swimming while we were there but around the tip of the peninsula near St. Klements is a bathing area, unfortunately it's concrete and not sand. We also saw some folks suiting up to go scuba diving, Piran is one of the coast's best spots for diving.
I think if it's beach activities you are after though, you'd be better off staying in nearby Portoroz.
Don't be disappointed and expect a beach in Piran - there isn't one. If you want to swim in the sea you are best advised to head down to Portoroz - there is a man-made beach there - otherwise from Piran you will have to clamber over the rocks which are used as sea defences to get into the water. Another word of warning there are a lot of jelly fish - whether they are poisonous or not, I can't tell but you have been warned!
The whole area around so-called Punta is the major beach resort of Piran. The water is wery clean and clear, however, you have to take care in case of big waves because the whole shore is ful of rocks.
Drew on the rocks
Ain't no big surprise...
Yes, it's an extremely rare photograph of yours truly. Normally, I'm the guy behind the camera, and that's probably best for everyone, since my friends are always more photogenic than I. However, this one's of me. Voila.
The sea near Piran is surprisingly nice - and the water clear... basically it screams for a swim. There's no real beaches in town but if you walk up to saint george's church and then take the footpath that goes downhill at the back, you'll arrive at a nice pebble beach from where you can swim out. Refreshing!
Equipment: Swimsuit - but it's optional